Selective calling/receiving device

Abstract

The result of detection performed by a receiving electric-field level detection circuit 8 and the result of detection performed by an automatic gain setting circuit 9 are fed back to a timing signal generation circuit 10 which controls a pre-heat time of a selective calling/receiving device. As a result, the pre-heat time can be changed according to the state of propagation of radio waves, and hence the life of battery of the calling/receiving device can be increased.

What is claimed is:  
     
       1. A selective calling/receiving device comprising: 
       a timing signal generation circuit for determining the control timing of intermittent receiving operations while ensuring a pre-heat time to render the device active by application of power to the device prior to a signal to be received, and  
       a receiving electric-field level detection circuit for detecting a receiving electric-field level,  
       wherein the timing signal generation circuit variably controls the pre-heat time so as to correspond to the receiving electric-field level detected by the receiving electric-field level detection circuit.  
     
     
       2. The selective calling/receiving device of claim  1 , further comprising: 
       a high-frequency amplifying circuit, and  
       an automatic gain setting circuit for setting a gain of the high frequency amplifying circuit, and  
       wherein the timing signal generation circuit variably controls the pre-heat time according to the gain set by the automatic gain setting circuit.  
     
     
       3. The selective calling/receiving device of claim  1 , further comprising: 
       a high-frequency amplifying circuit, and  
       an automatic gain setting circuit for setting a gain of the high frequency amplifying circuit, and  
       wherein the timing signal generation circuit variably controls the pre-heat time according to the detected receiving electric-field level and the amount of gain limited by the automatic gain setting circuit.  
     
     
       4. The selective calling/receiving device of claim  1 , further comprising: 
       an error rate detection circuit for detecting a bit error rate of received and demodulated data, wherein  
       the amount of gain limited by the automatic gain setting circuit is determined according to the thus-detected bit error rate.  
     
     
       5. The selective calling/receiving device of claim  1 , wherein the timing signal generation circuit decreases the pre-heat time when the detected receiving electric-field level increases.